1. Field of the Invention
The present invention is generally related to streaming multimedia quality, and more particularly to a system and computer program for evaluating streaming multimedia quality.
2. Discussion of the Background
Evaluating the quality of streaming multimedia as perceived by remote clients over delay tolerant networks is crucial for understanding the time variant quality of service (QoS) the underlying communication network is able to support. For instance, such information can be used by the content delivery providers (CDPs) for deducing the subjective level of satisfaction the end user is able to derive. Traditionally, such monitoring has been carried out by observing the variations of network dynamics along the dimensions of packet loss, delay and jitter. However, packet loss does not necessarily translate into poor viewing quality because whether a multimedia frame is correctly decoded may depend on the error-concealment techniques defined under the respective multimedia standards (e.g., MPEG-2, MPEG-4, and H.264). For example, for the same packet loss, a H.264 decoder might be able to correctly recover a multimedia frame which would have been discarded by an MPEG-2 decoder. In addition, the same packet loss will result in different multimedia quality for the same decoding technique.
Existing video evaluation tools use the peak signal-to-noise ratio (PSNR) and the mean opinion scores (MOS) in quantifying multimedia quality. However, the metric of PSNR cannot be used for real-time monitoring of video quality because the original (reference) multimedia stream is not available. Additionally, PSNR calculated on YUV data is based on analyzing the mean squared error (MSE) between individual pixels of the original and received frame. It is thus extremely computationally intensive and is impractical for real-time monitoring of multimedia quality. Similarly, the MOS metric that is recommended by the International Telecommunications Union (ITU) cannot be used for real-time monitoring of video quality because it requires the ranking of each multimedia stream by a large pool of online watchers and normalizing individual feedback on a pre-established scale.
Thus, as noted above, there currently exists deficiencies in evaluating streaming multimedia quality in the prior art.